Train-controlling system



H. A. MAXFIELD TRAIN CONTROLLING SYSTEM 1.922 8 she ts-sheet 1 FiledMarch 16.

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' H. A. MAXFIELD TRAIN GONTRIOLLINQ SYSTEM 8 Sheets-Sheet 2 Filed March16. 1922 March 4 @9240 H. A. MAXFIELD TRAIN CONTROLLING SYSTEM FiledMarch 16.

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H. A. MAXFIELD TRAIN CONTROLLING SYSTEM H. A. MAXFIELD TRAIN CONTROLLINGSYSTEM Filed March 16. 1922 8 Sheets-Sheet ,5

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' 1,485,563 H. A. MAXFIELD TRAIN CONTROLLING SYSTEM Filed March 16. 1922Sheets-Sheet e A ma 4W March 4 1924.

Filed March 16. 8 Sheets-Sheet March 4 1924.

H. A. MAXE-IELD TRAI N CONTROLLING SYSTEM Filed March 16, 1922 8 Shes t8 Patented Mar, 4, i924,

teases rarest sates,

HAROLD A. MAXFIELD, OF WORCESTER, L'IASSACHUSETTS, ASSIGNOR TO EZRA P.

W'AJIEJERI-IOUSE, OF WORCESTER, IEASSACHUSETTS.

TRAIN-CONTRQLLING SYSTEM.

Application filed March 16, 1922.

To all whom t't may concern.

Be it known that I, HAROLD A. MAXFIELD, a citizen of the United States,and a resident of Worcester, in the county of Worcester and State ofMassachusetts, have invented a new and useful Improvement inTrain-Controlling Systems, of which the following is a specification.

My invention, which is an improvement on the systems disclosed in thefollowing United States Letters Patent issued to the Orcutt AutomaticTrain Control Company, viz, Or-

cutt, No. 1,285,345, November 19, 1918, La'

Count, No. 1,336,?165, April 13, 1920, and Prince and La Count, Nos.1,336,484. April 13, 1920, and 1,342,572, June 8, 1920, to all of which,as well as to Patent No. 1,285,246 issued to said company November 19,1918, on the application of Eldridge I. La Count, reference may be madefor various details of construction not necessary to be specifically setforth herein, relates to systems for preventing railroad accidents suchas collisions, derailments, running on to open switches, etc., by meansof electrical apparatus and circuits carried by the train and arrangedto cooperate through track-connected contactmembers located in theblock-section in which the train is running with one of the advanceblocks, for example the block next ahead; and its general object is toimprove and simplify said systems and to increase the efficiency of thesame.

In such train controlling systems a nor mally-energized train-carriedair-brake-controlling electromagnet is deenergized and the air brakesautomatically applied when an advance block such as the block next aheadof that in which the train is running has been rendered unsafe from anycause as by a broken rail, an open switch or another traintherein; orwhen the road-bed circuit of such advance block is opened; or when atrain circuit is broken or the train apparatus short circuited orotherwise rendered incapable of properly functioning.

After such automatic application of the air brakes, the operation of thebrake-releasing valve, which is an adjunct to the envineers air-brakevalve and is automaticaly locked in running position when the trainspeed equals or exceeds a predetermined rate, will effect the release ofthe brakes, either after the train has been brought to a stand- SerialNo. 544,259.

still or when its speed has been reduced below said predetermined rate,and thereafter in either case the train is automatically prevented fromattaining a speed equaling or exceeding such predetermined rate until itpasses out of the block the condition of which caused the application ofthe brakes and then only in the event that the next block ahead is safe.

While it has been demonstrated that the systems aforesaid will properlyperform their intended functions under conditions of actual practice,they nevertheless involve certain complexities, the elimination of whichconstitutes the general object of the present invention. For example, insaid systems, the train-carried circuits are connected to certain trackcircuits and apparatus by means of at least two and sometimes three orfour contact shoes arranged to cooperate with at least two and sometimesthree or four ramps or contact plates arranged beside the track in eachblock, at least one of said ramps being connected by an overhead wire toa track switch located near the farther end of the block ahead of thatin which the ramp is placed.

A particular object of my invention is to provide a train controllingsystem wherein the train-carried circuits are connected to the rails ofthe block in advance of that in which the train is running solely bymeans of a single train-carried contact member arranged to cooperatewith a single track-connected contact member in each block and wherebythe air brakes will be automatically applied, and the train eitherbrought to a standstill or its speed reduced below a given rate, whensuch advance block has been rendered unsafe, and whereby, also, thespeed of the train, after such automatic application of the air brakes,is automatically main tained at less than said rate until the passage ofsaid train out of the unsafe block.

Another object of my invention is to dispense with the track switchlocated near the farther end of each block whereby the circuit of theair-brake-controlling magnet is controlled by substituting therefor atthe farther end of each block an electrical conductor which may be aresistance connecting the section of the sectional rail of said blockwith the electricallycontinuous rail, and a train-carried excess-currentmagnet connected to and disconnected from said resistance at a givenpoint in every block by the traincarried and track-connected contactmembers, said excess-current magnet actuating a switch which controlsthe circuit of the airbrake-controlling magnet, whereby the cost of thesystem is greatly reduced, the chances of failure in action diminishedand the amount of power required for operation decreased.

Another object of my invention is to reduce and simplify thetrain-carried circuits to render the system more positive in operationand less liable to fail in action.

A further object of my invention is to provide means for testing whethera railroad switch has been thrown completely one way or the other, tolock said switch from the block in the rear of that in which it islocated if it has been properly thrown, to unlock the same from a pointnear the switch, and to automatically apply the brakes if said switchhas not been properly set, all by the cooperation of the train-carriedcircuits and road-bed circuits.

\Vith the foregoing and other objects in view my invention comprises anair-brakecontrolling magnet normally energized by a train-carried sourceof electrical energy and means, consisting solely of a singletraincarried contact member electrically connected with the circuit ofsaid magnet and arranged for cooperation with a track-connected contactmember located in the block in which the train is running andelectrically connected with the rearward end of the sectional rail ofthe block next in advance, for momentarily breaking said circuit at apoint in the block in which the train is running and simultaneouslyconnecting the same in series with the rails of the block next inadvance, whereby the circuit of said magnet will be opened if said blockis unsafe for any of the reasons given above, said magnet deenergizedand the brakes applied to bring the train to a full stop or reduce thespeed thereof to a safe rate. It comprises also a speed-control switchhaving a magnet for moving the same to such position as to open thecircuit of the air-brake-controlling magnet, and a magnet for resettingthe same to its normal position, the circuit of the resetting magnetbeing normally open, and means whereby said circuit is closed throughthe rails of the block next ahead of that in which the train istraveling when such block is safe, said means comprising the aforesaidtrain-carried contact member normally in electrical connection with thecircuit of the air-brake-controlling magnet.

By means of the two component parts of the invention mentioned above asingle train-carried contact member is made to perform functions whichin the systems disclosed in the patents aforesaid required twotrain-carried contact members, viz., the functions of looping thetrain-carried circuits into the rails of the block ahead of that inwhich the train is traveling for the purpose of testing said block, andstopping the train if said block is unsafe or controlling the speedthereof.

My invention comprises also means for electrically connecting thefarther end of each section of the sectional rail with the continuousrail, such means preferably including a resistance approximately equalto a resistance normally included in the circuit of theair-brake-controlling magnet, and means electrically connecting each tackconnected contact member with the rearward end of the section of thesectional rail neXt in advance of the section between the ends of whichsaid contact member is located, together with an excess-current magnetcontrolling a switch which normally closes the circuit of theair-brake-controlling magnet, the circuit of said excess-current magnetbeing closed once in every block through the rails of the block next inadvance of that in which the train is running, whereby should saidresistance be short circuited by a train in said block, saidexcess-current magnet will cause said switch to break the circuit of theair-brake-controlling magnet and the brakes thereby will be applied.

By means of this feature the cost of the system is greatly reduced bythe elimination of a track switch at the end of each block section, theamount of power required for operating the system is decreased and thesystem is rendered more positive in action. Furthermore by means of saidfeature and those already mentioned the train-carried circuits,especially those which relate to the speed controlling apparatus, aresubstantially reduced and simplified.

My invention further comprises electromagnetic switch-locking mechanismcon trolled by the cooperation of the train carried circuits androad-bed circuits at a point in the block preceding that in which theswitch is located, switch-unlocking means controlled by the cooperationof said circuits at a point near the switch, and an electric switchactuated by said mechanism whereby the eletrical continuity of thesectional rail of the block in which the switch is placed will bebroken, if the switch has not been properly set and the brakesautomatically applied.

Various other features of novelty will hereinafter be described andparticularly set forth in the appended claims.

The drawings which accompany and form a part of this specificationdiagrammatically represent several embodiments of the inven tion; but itwill be understood that both the apparatus and circuit arrangementstherein conventionally shown may be materially modified by those skilledin the art without departing from the invention as defined by theappended claims.

In the drawings,-

Figure 1 shows a train controlling system with its several parts shownin the positions occupied when the train is running at or above apredetermined speed in an unoccu pied block, the track conditions ofwhich are good, and before the train circuits are connected with therails of the block next in ad vance;

Fig. 2 shows the system when the train circuits are connected to therails of the block next ahead of that in which the train is running,said block being clear and the track conditions good;

Fig. 3 shows the system when the train circuits are connected with theblock next ahead, one or both of the rails thereof, or their electricalcontinuity being broken;

Fig. a shows the system when the train circuits are connected with theblock next ahead which is occupied by another train, theairbrake-setting valve having the position occupied immediately beforethe de-energization of the air-brake-controlling magnet;

Fig. shows the system after the circuits have been disconnected from theoccupied block next ahead and the train has been brought to astandstill, the air-brake-setting valve having the position occupiedimme diately before the reenergization of the airbrake-controllingsystem;

Fig. 6 shows the system when the train is runing under control below apredetermined rate of speed in an occupied blocr;

Fig. 7 shows the system when the train circuits are connected to a safeblock next ahead after it has run under control through a portion of thepreceding block, the speed control switch being about to be reset;

Fig. 8 shows the system provided with circuits and apparatus for lockinga railroad switch from a point in the bloclr in the rear of that inwhich such switch is located and for unlocking said switch from a pointnear the same, the parts being shown in the positions occupiedimmediately before the switch-locking apparatus has operated.

In the particular drawings selected for more fully disclosing myinvention each block section, about one-half mile in length, consists ofthe rail 1, the joints of which are bonded to insure electricalcontinuity, and a rail 2, the component parts of which are alsoelectrically bonded, but the sections of which are insulated from theadjacent sections 2, 2". The forward end of each section of thesectional rail is electrically connected to the continuous railpreferably through the resistance 3, 3. Located between the ends of eachsectional rail and preferably at a point some distance from the forwardend thereof, for example about one thousand feet, is a track-connectedcontact member 4:, a", said contact member being shown herein by way ofexample as a ramp or contact plate or rail arranged parallel to thetrack rails and adjacent to either one thereof so that a train-carriedcontact member will cooperate therewith during the passage of the trainthrough the block. The contact members 4, 4 are connected, respectively,to the rearward end of, the section of the sectional rail next inadvance of the same by the conductors 5, 5" preferably carried by thetelegraph poles beside the track, or as hereinafter explained a portionof the sectional rail of the adjacent track may be used for thispurpose.

The train equipment includes an adjunct to the engineers air-brake valvesuch for example as shown in Patent No. 1,2852% above referred to, aportion of said adjunct being represented in Fig. 1 and comprising acasing having a passageway 6 normally closed by the brake-setting valve7 but open to the atmosphere through the passage 8 when said valve isoil its seat. Said adjunct comprises also a casing 9 enclosing abrakereleasing valve pneumatically operated and controlled by the handle10, the partial rotation of which serves to connect the brakerele-asingvalve chamber with a pipe connected to the main compressed airreservoir.

The brake-setting valve 7 is actuated by the air-brake-controllingmagnet 11, said magnet preferably being of the sheathed, hollow-coresolenoid type and having an armature 12 secured to its plunger 13 whichcarries the valve 7, said armature being movable between the lower endof the sheath 14 and the backstop 15.

The circuit of the train-controlling magnet is normally closed andincludes a source of electrical energy such as the direct currentgenerator 16 carried by the train.

Carried by or otherwise associated with the plunger of theair-brake-controlling magnet is a switch 17 herein shown as of thecommutator type, said switch consisting of an insulation member 18provided with two conducting rings 19, 20 with which the brushes 21, 22and 23, 24, respectively, are arranged to co-operate for the purpose ofclosing certain circuits through said rings.

An excess-current magnet 25 herein shown as having a normally-opencircuit is so arranged that its armature 26 is normally held away fromthe enclosing sheath 27, in the present instance a spring 28 arranged ina cylinder 29 and adjustable by the screw 30 serving to maintain thearmature 26 in the position shown and prevent the oscillation of thesame by the vibration or swaying of the train, and the lowermostposition of said armature being governed by the head or piston 31arranged in said cylinder and attached to the upper end of the magnetplunger. Arranged for actuation by said excess-current magnet is aswitch 32 consisting in the present instance of an insulation member 33carrying a conducting ring 34 arranged for cooperation with the brushes35, 36.

A speed-control switch 37 consisting in the present instance of theplunger carrying the insulation member 38 and conducting ring 39arranged for cooperation with the brushes 40, 41 is controlled by theactuating magnet 42 and the resetting magnet 43 which when energizedattract the armatures 44, 45 respectively.

Operatively connected by the bevel gear 46 with a rotating element ofthe engine is a centrifugally actuated switch 47, said switch in thepresent instance consisting of an insulating cylinder carrying theconducting rings 48, 49 arranged for cooperation, respectively, with thebrushes 50, 51 and 52, 53. The ring 49 is shown as adjustablelongitudinally of the said insulation memher, the set screw 54 servingto hold the same in adjusted position, although it will readily beunderstood that said ring may be fixed and the brushes 52, 53 arrangedfor adjustment longitudinally of said ring. In like manner the brushes50, 51 and their cooperating conducting ring 48 are arranged foradjustment longitudinally of said insulating cylinder either by movingsaid ring with respect to the brushes or, conversely.

A switch 55 consisting in the present instance of an insulating membercarrying the conducting rings 56, 57 both of which are electricallyconnected with the conducting rod 58 the lower end of which is always inelectrical contact with the train-carried contact member 59 is arrangedto be actuated by said contact member which as shown in Fig. 1 consistsof a downwardly curved member of spring material fixed at one end to aportion 60 ot the locomotive and having its other end maintained by itsown elas ticity against the stop 61 secured to the portion 62 of thelocomotive. The brushes 63, 64 are arranged "for cooperation with theconducting rings 56, 57 respectively. A locking magnet 65 is arranged toactuate its plunger 66 and force the same through registering aperturesbored in the extensions of the handle 10 and easing 9 of theairbrake-releasing valve, said plunger falling by gravity against thebackstop 67 upon the deenergization of said magnet and thereby unlockingsaid handle.

When the traincarried contact member 59 is of? the track-connectedcontact mem her 4 and the train is running under normal conditions therewill be a circuit through the air-brakecontrolling magnet 11 as follows:From the positive terminal of the generator to wires 68, 69, winding 11,wire 70,

brush 35, ring 34, brush 36, wire 71, brush 40, ring 39, brush 41, wires72, 80, rod 58, ring 56, brush 63, resistance 81, which is equalapproximately to the resistances 3, 3, and thence back to the negativeterminal of the generator by the wire 82. The handlelock magnet 65 willbe closed through the wire 68, winding 65, brush 52, ring 49, brush 53and wire 83 connected to the negative terminal of the generator. As longas the train travels at a speed equal to or exceeding a predeterminedrate the governor of the centrifugally-actuated switch maintains theconducting ring 54 in cooperation with the brushes 52, 53 and therebythe circuit of the locking magnet is kept closed and the handle locked.

The circuit of the excess-current magnet 25 is open at the brush 64 inthe arrange ment shown in Fig. 1 although it will be understood ofcourse that the wire 84 if disconnected from the winding 43 may beconnected to the wire or the rod 58 so as to maintain the normalenergization of said magnet 25,the magnetic pull resulting from. suchnormal energization not being sufiicient to overcome the compression ofthe spring 28. There will be a circuit through the white or safetysignal lamp 85 by way of the wires 68, 69, 86, brush 21, ring 19, brush22, lamp 85 and wires 87 82.

The circuits of the actuating magnet 42 and resetting magnet 43 of thespeed-control switch are both open.

When the train-carried contact member 59 strikes and runs along thetrack-connected contact member 4, the switch 55 is raised to theposition shown in Fig. 2, one of the insulating portions of said switchis brought against the brush 63 thereby breaking the normally-closedcircuit of the air-brake-controlling magnet and simultaneously closingit through the block 2 next in advance of that in which the contactmember 4 is located, and if said block 2 is clear and the trackconditions good the resistance 3 at the end thereof, being theequivalent of the resistance 81 cut out of the circuit of saidairbrake-controlling magnet by said switch 55, will prevent anysubstantial change in the current flowing through said magnet, and thevalve 7 will be maintained on its seat. Under these conditions thecircuit through the magnet 11 is from the positive terminal of thegenerator to the wires 68, 69, winding 11, wire 70, ring 34, wire 71,ring 39, wires 72, 80, rod 58, contact shoe 59, ramp 4, overhead wire 5,sectional rail 2, resistance 3, continuous rail 1 and thence back to thegenerator by way of the contact member 88, shown as one of the wheels ofthe locomotive, and the wire 82. The handle 10 will remain locked andthe white light 85 will continue burning. There will be a circuitthrough the excess-current magnet 25 by way of the wires 68, 69, 86,brush 21, ring 19, brush 22, winding 25, wires 84, 89, brush 64, ring57, rod 58, shoe 59, ramp 4, overhead wire 5, sectional rail 2,resistance 3, continuous rail 1, contact member 88 and wire 82. Themagnet 25 is so designed that when the resistance 8 is included in itscircuit as above pointed out the current flow therethrough is notsuliiciently strong to cause the armature 26 to rise against theopposing force of the spring 28 so that the circuit of theairbrake-controlling magnet is maintained between the ring 34 andbrushes 85 and 86. Conditions being normal the train passes out ofsection 2 and through section 2 at full speed.

If however block 2 should have been ren-' dered unsafe by a broken railas indicated in Fig. 3 the air brakes will be automatically applied assoon as the train-carried contact member strikes the track-connectedcontact member 4, so that the train will either be brought to a fullstop or its speed maintained below a predetermined rate. One or both ofthe rails of block 2 being assumed to be broken so as to destroy theelectrical continuity of the circuit formed in part by said rails, thecircuit of the air-brake-controlling magnet is opened at the point wherethe rail is broken whereupon the resulting deenergization of said magnetwill cause the valve 7 to drop from its seat thereby effecting theapplication of the brakes in the manner set forth in Patent No.1,285,246 above mentioned. The armature 12 falling back to the stop 15car "ies the switch 17 to the position shown in Fig. 3 thereby breakingthe circuit of the white or safety signal lamp and closing the circuitof the red or danger signal lamp 89 through the wires 68, 69, 86, 89,90, said lamp 89', brush 23, ring 20, brush 24, wires 87 and 82. Thecircuit of the excess-current magnet will be opened at the broken rail.The actuating magnet 42 of the speed-control switch 37 will be energizedby way of the wires 68, 69, 86, 90, 91, 92, winding 42, wires 93, 94,95, ring 20, wires 87 and 82, and thereupon said speed-control switch isshifted to the right as indicated in Fig. 3. This movement of thespeed-control switch will bring one of the insulating portions of thespeed-control switch in contact with the brushes 40, 41 thereby openingthe circuit of the air-brake-controlling magnet at said switch. As soonas the shoe 59 runs off the ramp 4 the circuit of theair-brakecontrolling magnet would instantly be closed between the brush63 and ring 56 were it not for the movement of the speed-control switchto the position shown in Fig. 3, and in such case the operation of thehandle 10 would effect the release of the brakes so that the train couldbe driven through the dangerous block at full speed. Shortly after uponthe application of the air brakes as aforesaid thecentrifugally-actuated switch 47 will break the circuit of thehandle-locking magnet 65 between the brushes 52, 53 and the insulatingcylinder upon which they are mounted. In Fig. 3 showing the position ofthe parts at the instant of cooperation of the contact members 59 and 4,the speed of the train has not been sufficiently reduced to cause thecentrifugal switch to drop to its lowermost position, such positionbeing shown in Fig. 5; but this position will be assumed by said switchvery shortly after the contact member 59 passes the contact member 4,and when this takes place, the handle is unlocked thereby permitting therelease of the brakes. Means are provided whereby after the release ofthe brakes the train will be prevented from running at or above apredetermined rate, said means in the present instance consisting of theshunt circuit 96, 97 connected around the speedcontrol switch andincluding the brushes 50, 51. When the train is stationary and up to thetime it acquires a predetermined speed the said brushes 50, 51 will bein contact with the ring 48 thereby closing the shunt circuit aforesaidand, consequently, the circuit of the train-controlling magnet 11, thelatter then being as follows :-wires 68, 69, winding 11, ring 34, wires71, 96, ring 48, wires 97, 80, rod 58, ring-56, brush 63, resistance 81and wire 82. The engineer having released the brakes by the operation ofhandle 10 may therefore run his train out of block 2 and through block 2at a speed below said predetermined rate this being known as creeping upto the point of danger; but should he attemptto drive the train at aspeed equal to or higher than said rate the circuit of the magnet 11would be broken at the brushes 50, 51 and the brakes again automaticallyapplied.

If the block 2 is occupied as indicated at 98 when the contact member 59strikes the ramp 4 in the block in the rear of block 2, the brakes willbe applied in the following manner: The excess-current magnet 25 will beover-energized by way of the wires 68, 69, 86, brush 21, ring 19, brush22, winding 25, wire 89, brush 64, ring 57, rod 58, shoe 59, ramp 4,overhead wire 5, the trucks 98 of the train in the block 2 (or any othermetal lic obstruction on the rails which short circuits the resistance3) rail 1, rolling contact 88 and wire 82, and will raise the switch 32against the action, of the spring 28 thereby breaking the circuit of theair-brakecontrolling magnet between the brushes 35, 36, and theinsulation portion of said switch. Figure 4 shows the first instant ofoperation of the excess-current magnet, and immediately after the switch32 actuated by said magnet has taken the position shown in Fig. 4, thevalve 7 falls from its seat thereby applying the air brakes, the circuitof the tuating magnet 42 of the speed-control switch 37 is closed in themanner above set forth in connection with Fig. 8, thereby throwing saidswitch to the right, and shortly thereafter the centrifugally-actuatedswitch 47 will drop to its lowermost position, as shown in Fig. 5,thereby breaking the circuit of the locking magnet 65 and closing theshunt 96, 97 around the speedcontrol switch.

As soon as the contact member 59 has passed over the ramp 4, as shown inFig. 5, the circuit of the excess-current magnet is opened and theswitch 32 drops to its normal position. When the speed of the train hasbeen sufficiently reduced to close the shunt 96, 97 around thespeed-control magnet 37, the air-brake-controlling magnet will. beenergized and the valve 7, shown off its seat in Fig. 5, will be raisedto close the port controlled thereby. Figure 5 shows the first instantof closure of said shunt 96, 97, following the deenergization of theexcess-current magnet, the several moving parts being shown in thepositions occupied immediately before the reenergization of the mag net11. The positions of the moving parts shown in Fig. 5 are those whichthey assume when the train has been brought to a full stop (it beingunderstood that said valve 7 is on its seat as soon. as the shunt 96, 97is closed) or while it is traveling under control at a safe speed out ofthe block 2 and into the unsafe block 2.

Figure 6 illustrates the system when the train is running under controlbelow a pre determined speed through the occupied block 2. Theair-brake-controlling valve is closed by way of the shunt 96, 97 asabove explained and therefore as long as the rate of travel issufiiciently low to keep the ring 4-8 in contact with the brushes 50, 51the train can proceed through said block; but as soon as it equals orexceeds the predeiermined rate the shunt 96, 97 will be broken at thebrushes 50, 51 thereby deenergizing the magnet 11 and automaticallysetting the brakes. It will be understood that upon the application ofthe brakes for any cause it is not necessar for the engineer to waituntil the train has been brought to a full stop before releasing thesame by means of the handle 10, for as soon as the speed of the trainhas been sufficiently reduced to break the. circuit of the lockingmagnet 65 at the brushes 52, 53, thereby unlocking said handle, thebrakes may be released in the manner above set forth, and the traindriven at a safe speed below said predetermined rate.

After the train has run under control through a block the condition ofwhich caused the application of the brakes, such as the block 2 thespeed control switch 37 will be reset in the following manner:

efe

messes ring to Fig. 7 which shows the Contact member 59 on the ramp 4connected by the overhead wire 5 to the rearward end of the sectionalrail 2", the forward-end of which is connected to the continuous rail bythe resistance 3", the circuit of the resetting magnet 43 is closedthrough the wires 68, 69, 86, 99, 91, 92, winding 43, wire 89, brush64-, ring 57, shoe 59, ramp 4', wire 5", rail 2", resistance 3", rail 1,rolling contact 88 and wire 82. The energization of said resettingmagnet L3 will throw the speed-control switch 37 to the left, theposition shown in Fig. 1, and will close the circuit of theairbrake-controlling magnet through the brushes 40, 41 and ring 39,whereupon the train is free to proceed at full speed, the circuit ofsaid air-brakecontrolling magnet being new independent of the shunt 96.97. Assuming that the train proceeds at full. speed upon. the resettingof the S1386Cl-0011- trol switch, the centrifugally-actuated switch 457will assume the position shown in Fig. 1, said shunt will be opened andthe handle 10 locked in running position. It will b understood of coursethat if the block 2" were not clear and the track conditions were notgood the speed-control switch would not be reset and the operationsabove set forth in connection with Figs. 3 and. 4: would be carried out.

It will be noted. that the means whereby the normally-closed circuit ofthe air-brakecontrolling magnet is broken at a point in each. block andsimultaneously connected in series with the rails of the block next inadvance consist solely of the train-carried contact member 59 and thetrack-connected contact member 4 as distinguished from the systems shownin the patents above referred to in which at least two train-carried.contact shoes are required, one such shoe closing the circuit of a trackswitch located at or near the forward end of the block in advance ofthat in which the train is traveling whereupon if said block is clearand the track conditions good the second shoe cooperating with anotherramp connects the air-brake-controlling magnet in series with a circuitconsisting in part of the continuous rail, the sectional rail at no timeforming a part of the circuit of said magnet; also that thetrain-carried contact member is connectec not only with the circuit ofthe airbrake-controlling magnet but also with the circuit of themagnetic means controlling the specd-control magnet, so that a singletrain-carried contact member performs the functions which require twosuch contact members in the system described in Patent 1,336,465aforesaid; and also that the excess-current magnet is arranged to openthe circuit of the air-brake-controlling magnet only when saidaccess-current magnet is over-energized as distinguished from the systemdisclosed in Patent 1,285,345 aforesaid in which the magnet controllingthe air-brake-controlling magnet is arranged to open the circuit of saidair-brake-controlling magnet upon its under-energization as well as uponits over-energization, this requiring an impracticably-fine adjustment.By virtue of the elimination of the track magnets of the prior art, oneat the forward end of every block and the substitution therefor of thetrack resistances 3 together with the employment of the excess-currentmagnet and the switch actuated thereby, the cost of the system isgreatly reduced and its action is made more certain and positive, theonly moving parts of the system being under the direct supervision ofthe engineer.

In Fig. 8 I show an adjunct to the system above described whereby thebrakes willbe automatically applied when the train is in a given blockif a rail switch in the block ahead is open, and whereby said switch maybe locked in either position by the cooperation of the train and trackcircuits when the train is in the block in the rear of said switch andsubsequently unlocked shortly before or immediately after the trainpasses the same. The ramp 99 placed a short distance in the rear of theramp 4 located as above set forth some distance in the rear of theforward end of section 2 is connected by the wire 100 to theswitch-locking magnet 101 the other terminal of which is connected tothe continuous rail by the wire 102. Located near the rail switch and inthe present instance shown as a short distance in the rear thereof,although obviously it might be placed a short distance forward of thesame, is a ramp 103 connected by the wire 104 with the switch-unlockingmagnet 105 the other terminal of which is connected to the continuousrail by said wire 102. A tuated by the plunger of the magnets 101, 105is a switch 106 consisting in the present instance of an insulationmember provided with a conducting ring 107 arranged for cooperation withthe brushes 108, 109 which are connected by the wires 1-10, 111respectively with the two insulated portions 2, 2 of the sectional rail2. For simplicity of illustration the track switch is represented as astub switch 112 the rails of which are pivoted. at 113, the free ends ofsaid rails sliding over the plates 11 1 electrically con nected with therails of the forward portion of the section by the bonds 115. The bond116 diagrammatically represents means for maintaining the electricalcontinuity of section 2", it being understood that in practice the frogwill be so constructed as to render such bond unnecessary. By means ofthe lever 117 pivotally connected to the switch bar 118 and to the tierod 119 pivoted to the two switch rails, the switch may be hrown toeither position. The operation is as follows: When the shoe 59encounters the ramp 99 there will be a circuit through theswitch-locking magnet 101 from the positive terminal of the generator 16by way of the wires 68, 69, winding 11, ring 34, wire 71, ring 39, wires72, 80, rod 58, shoe 59, ramp 99, wire 100, winding 101, wire 102, rail1, rolling contact 88 and wire 82. The resulting energization of saidwinding 101 will attract the shuttle armature 120 and throw the plunger121 to the right so that if the switch is properly set the bolt willpass through one of the apertures 122 or 123 in the switch bar dependingupon whether the switch is in main-line or switching position,respectively. It will be understood that the opening of the switch willnot break the metallic continuity of the sectional rail 2 or of thecontinuous rail 1 so that the circuit of the air-brake-controllingmagnet would not be opened when the contact member 59 encounters theramp 4.- merely on account of the opening of the switch; but unless suchswitch is locked either in one position or the other, theairbrake-controlling -magnet will be deenergized and the brakesautomatically applied as soon as the contact member 59 strikes the ramp4 placed as aforesaid about one thousand feet in the rear of the blockin which the switch is located. The energization of the switch-lockingmagnet 101 and the result ing movement of the plunger 121 to the rightwill close the shunt circuit 110, 111 through the brushes 108, 109 andthe ring 107 thereby electrically connecting the two insulated. portions2*, 2 of the sectional rail 2. Immediately thereafter the contact member59 encounters the testing ramp t and the conditions will be identicalwith those above set forth in connection with Fig. 2 if block 2 is safeor those above explained in connection with Figs. 3 and 1 if said blockis occupied or the rails thereof broken. If. however the rail switchshould be open, that is, not properly thrown to one position or theother, the bolt 121 cannot enter either aperture 122, 123 and thereforethe switch 106 cannot be moved to the position necessary for closing theshunt 110, 111. The electrical continuity of the sectional rail of block2 being thus destroyed, the brakes will automatically be applied as soonas the shoe 59 encounters the ramp 4- in the manner above set forth inconnection with Fig. 3, and the train brought to a full. stop or elseprevented from passing through block 2 except at a speed lower than apredetermined rate.

When the contact member 59 cooperates ramp 103, wire 104i, winding 105,wire 102, rail 1, rolling contact 88 and wire 82, whereupon the shuttlearmature 120 will be attracted by the electromagnet 105 and the plungerthrown to the left in the position shown in Fig. 8, thereby unlockingthe rail road switch. Preferably the electromagnets 101, 105 and theirshuttle armature 120 are constructed in the manner shown in Patent1,285,345, the windings 101, 105 being stationary and the plunger towhich the armature 120 is fixed having a sliding fit in the bores of thefixed cores around which said windings are wound.

The resistance of the switch-locking and unlocking magnets 101, 105shown in Fig. 8 should have approximately the same value as the blockresistance 3 or about one half of the total circuit resistance so thatwhen the train-carried circuits are looped into the circuits of saidmagnets by the co-operation of the contact shoe with the ramps 99 and103' respectively the effect will be substantially the same as when saidtrain-carried circuits are looped into the circuit formed by the railsand the resistance 3 by the co-operation of the contact shoe and ramp4:.

It will be noted that while three ramps are required in the system shownin Fig. 8, only one train-connected contact member wi ll suflice toperform the functions of the two contact shoes of the system disclosedin patent 1,285,345 and that the road-bed circuit arrangements of mysystem are much more simple than those of the system of said patent, andfurthermore that the circuits of the switch-locking and unlockingmagnets are independent of the switch 106 governing the electricalcontinuity of the insulating portions of the sectional rail.

Having thus described illustrative embodiments of my invention withouthowever limiting the same thereto, what I claim and desire to secure byLetters Patent is 1. A train controlling system comprising incombination an electrically-continuous rail and a sectional rail, eachsection of which is electrically continuous but insulated from itsadjacent sections, a source of electrical energy carried by the train,an air-brakecontrolling magnet normally energized by said source, andmeans whereby the normallyclosed circuit o'f'said magnet is broken at apoint in the block in which the train is run ning and simultaneouslyconnected in series with the rails of the block next in advance, saidmeans consisting solely of a single traincarried contact memberelectrically connected with said circuit and a single track-connectedcontact member located in the block in which the train is running andelectrically connected with the rearward end of the sectional rail ofthe block next in advance.

2. A train controlling system comp ising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, asource of electrical energy carried by'the train, anair-brakecontrolling magnet normally energized by said source,electromagnetic means for reducing the speed of the train to less than apredetermined rate after the de-energization of saidair-brake-controlling magnet and the resulting automatic application ofthe air brakes and for maintaining such speed at less than said rateduring the passage of the train up to and out of the block the condition of which caused the application of the air brakes, means actuatedby said air-brakecontrolling magnet for controlling said electromagneticmeans, and means whereby the normally closed circuit of saidair-brake-controlling magnet is broken at a point in the block in whichthe train is running and simultaneously connected in series with therails of the block next in advance, said means consisting solely of asingle train-carried contact member electrically connected with saidcircuit and a single track-connected contact member located in the blockin which the train is running and electrically connected with therearward end of the sectional rail of the block next in advance.

3. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, asource of electrical energy carried by the train, an airbrake-controlling magnet normally energized by said source, aspeed-control switch, an actuating magnet and a resetting magnet forcausing said speed-control switch to open and close the circuit of saidair-brake-controlling magnet, respectively, and means whereby thenormally-closed circuit of said air-brake-controlling magnet is brokenat a point in the block in which the train is running and simultaneouslyconnected in series with the rails of the block next in advance, saidmeans consisting solely of a single traincarried contact memberelectrically connected with said circuit and with the circuit of saidresetting magnet and a single track-connected contact member located inthe block in which the train is running and electrically connected withthe rearward end of the sectional rail of the block next in advance.

4;. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, asource of electrical energy carried by the train, anairbrake-controlling magnet normally energized by said source, aspeed-control switch, an actuating magnet and a resetting magnet forcausing said speed-control switch to open and close the circuit of saidair-brake-con' trolling magnet, respectively, a switch actuated by saidair-brake-controlling magnet, for controlling the circuit of saidactuating magnet, and means whereby the normally-closed circuit of saidair-brakecontrolling magnet is broken at a point in the block in whichthe train is running and simultaneously connected in series with therails of the block next in advance, said means consisting solely of asingle train-carried contact member electrically connected with thecircuits of said air-brakecontrolling magnet and said resetting magnet,and a single track-connected member located in the block in which thetrain is running and electrically connected with the rearward end oi?the sectional rail of the block next in advance.

5. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, asource of electrical energy carried by the train, anair-brake-controlling magnet normally energized by said source, aspeed-control switch, an actuating magnet for causing said speedcon-trolswitch to open the circuit of said air-brake-controlling magnet, aresetting magnet for causing said speed-control switch to close thecircuit of said air-brake-contr'olling magnet, a single train-carriedcontact member connected with the circuit of said air-brake-controllingmagnet and with the circuit of said resetting magnet, and a singletrack-connected contact member located in the block in which the trainis running and electrically connected with the rearward end of thesectional rail of the block next in advance.

6. A train controlling system comprising in combination anelectricallycontinuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, asource of electrical energy carried by the train, an air-brakecontrolling magnet normally energized by said source, a speed-controlswitch, electro magnetic controlling means for said speedcontrol switch,a train-carried contact member, a track-connected contact memberarranged for co-operation with said train-carried contact member andmeans electrically connecting said train-carried contact memher with thecircuits of said air-brake-com trolling magnet and said electromagneticcontrolling means.

7. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, asource of electrical energy carried by the train, anairbrake-controlling magnet normally energized by said source, aspeed-control switch,

an actuating magnet and a resetting magnet for causing saidspeed-control switch to open and close the circuit of saidair-brake-controlling magnet, respectively, a shunt circuit connectedaround said speed-control switch, means for closing said shunt circuitwhen the train is stationary or the speed thereof is less than apredetermined rate and thereby closing the circuit of saidair-brake-controlling magnet after the same has been opened by saidspeed-control switch, and means whereby the normally-closed circuit ofsaid air-brake-controlling magnet is broken at a point in the block inwhich the train is running and simultaneously connected in series withthe rails of the block next in advance, said means consisting solely ofa single train-carried contact member electrically connected with thecircuits of said air-brakecontrolling magnet and said resetting magnetand a single track-connected contact member located in the block inwhich the train is running and electrically connected with the rearwardend of the sectional rail of the block next in advance.

8. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, asource of electrical energy carried by the train, anairbrake-cont-rolling magnet normally energized by said source, aspeed-control switch, an actuating magnet and a resetting magnet forcausing said speed-control switch to open and close the circuit of saidair-brakecontrolling magnet, respectively, a shunt circuit connectedaround said speed-control switch, a centrifugally actuated switch forclosing said shunt circuit when the train is stationary or the speedthereof is less than a predetermined rate and thereby closing thecircuit of said airbralie-controlling magnet after the same has beenopened by said speed-control switch, and means whereby thenormally-closed circuit of said air-brakecontrolling magnet is broken ata point in the block in which the train is running and simultaneouslyconnected in series with the rails of the block next in advance, saidmeans consisting solely of a single train-carried contact memberelectrically connected with the circuits of said air-brake-controllingmagnet and said resetting magnet and a single track-connected contactmember located in the block in which the train is running andelectrically connected with the rearward end of the sectional rail ofthe block next in advance.

9. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brake-controlling magnetnormally energized by said source, an excess-current magnet, a switchactuated by said excess-current magnet, said switch normally closing thecircuit of said airbrake-controlling magnet and being ar ranged to opensaid circuit only when the current in said excess-current magnet exceedsa given intensity, and a switch actuated by said air-brake-controllingmagnet, the last mentioned switch having its contacts connected in thecircuit of said excess-current magnet.

10. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an airbrake-controlling magnetnormally energized by said source, an excess-current magnet, a switchactuated by said excess-current magnet, said switch controlling thecircuit of said air-brake-controlling magnet, and a switch actuated bysaid air-brake-controlling magnet for con trolling the circuit of theexcess-currei'it magnet 11. A train controlling system comprising incombination a source of electrical energy carried by the train, anair-brake-controlling magnet normally energized by said source, a secondmagnet, a switch actuated by said second magnet for controlling thecircuit of the air-brake-controlling magnet, and a switch actuated bythe air-brake-coir trolling magnet "for controlling the circuit of saidsecond magnet.

12. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brakecontrolling magnetnormally energized by said source, an excess-current magnet, a switchactuated by said excess-current mag net, said switch normally closingthe circuit of said airbral :e-controlling magnet and being arranged toopen said circuit only when the current in said excess-current magnetexceeds a given intensity, a speed-control switch normally closing thecircuit of said air-brake-controlling magnet, a train-carried contactmember, and a switch actuated by said train-carried contact member andnormally closing the circuit of said air brake-controlling magnet.

13. A train controlling system compris ing in comt'nation a source oielectrical energy carried by the train, an air-brake controlling magnetnormally energized by said source, an excess-current magnet, a switchactuated by said excess-current magnet, said switch normally closing thecircuit of said airbrake-controlling magnet and being arranged to opensaid circuit only when the current in said excess-curent magnet exceedsa given intensity, a speedcont-rol switch normally closing the circuitor" said air-brake-controlling magnet, a shunt circuit connected aroundsaid speedcontrol switch, means for closing said shunt circuit when thetrain is stationary or the speed thereoi is less than a predeterminedrate, a train-carried contact member and a switch actuated by saidtrain-carried contact member and normally closing the circuit of saidair-brakecontrolling magnet.

14. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brakecontrolling magnetnormally energized by said source, a normally-open-circuited'excess-current magnet, and a switch actuated by said excess-currentmagnet, said switch normally cl sing the circuit of saidairbrake-controlling magnet and being arranged to open said circuit onlywhen the current in said excess-current magnet exceeds a givenintensity.

train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brake-controlling magnetnormally energized by said source, a normally-open-circuitedexcesscurrent magnet connected in parallel with saidaii'--brake-controlling magnet, and a switch actuated by sainexcess-current magnet, said switch normally closing the circuit of saidair-bralte-controlling magnet and being arranged to open said circuitonly when the current in said excesscurrent magnet exceeds a givenintensity.

16. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, anelectrical connection from the forward end of each section of saidsectional rail to said continuous rail, a track-connected contact memberlocated between the ends of each section of said sectional rail at apoint some distance from the forward end thereof, means connecting eachsaid contact member to the rearward end of the section oi said sectionalrail next in advance of the same, a source of electrical energ 1 carriedby the train, an air-brake-controlling magnet normally energized by saidsource, a .normally-open-circuited excess-current magnet, a switchactuated by said excess-current magnet, said switch normally closing thecircuit of said air-brake-controlling magnet, and a traincarried contactmember connected to the circuits of said air-brakecontrolling magnet andsaid excess-current magnet and arranged to co-operate with saidtrack-connected contact member.

17. A train controlling system comprising in combination, a source ofelectrical ene y carried by the'train, an air-brakecontrolling magnetnormally energized by said source, a normally-open-circuitedexcess-current magnet, a swi t-ch actuated by said excess-currentmagnet, said switch normally closing the circuit of said air-brakecontrolling magnet and being arranged to open said circuit only when thecurrent in said excess-current magnet exceeds a given intensity, andmeans whereby the normallyopen circuit of said excess-current magnet isclosed once in every block through conductors comprising the rails ofthe block next in advance.

18. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulat-ed from its adjacent sections, anelectrical connection from the forward end of each section of saidsectional rail to said continuous rail, a tracloconnected contact memberlocated between the ends of each section of said sectional rail at apoint some distance from the forward end thereof, means connecting eachsaid contact member to the rearward end of the section of said sectionalrail next in advance of the same, a source of electrical energy carriedby the train, an air-brake-controlling magnet normally energized by saidsource, a normally-open-circuited excess-current magnet, a switchactuated by said excess-current magnet, said switch normally closing thecircuit of said air-brake-controlling magnet, and means whereby thenormally-open circuit of'said excess-current magnet is closed once inevery block through the sectional rail of the block next in advance,said electrical conductor and said continuous rail.

19. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail, each section of whichis electrically continuous but insulated from its adjacent sections, anelectrical connection from the forward end of each section of saidsectional rail to said continuous rail, a track-connected contact memberlocated between the ends of each section of said sectional rail at apoint some distance from the forward end thereof, means connecting eachsaid contact member to the rearward end of the section of said sectionalrail next in advance of the same, a source of electrical energy carriedby the train, an air-brakecontrolling magnet normally energized by saidsource, a normally-0pencircuited excess-current magnet, a switchactuated by said excess-current magnet, said switch normally closing thecircuit or" said air-brakecontrolling magnet and being arranged to opensaid circuit only when the current in said excess-current magnet exceedsa given intensity, and a train-carried contact member connected to thecircuit of said excesscurrent magnet and arranged to co-operate withsaid track-connected contact member.

20. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brake-controlling magnetnormally energized by said source,

a normally-open-circuited excess-current magnet, a switch actuated bysaid excesscurrent magnet, sa d switch normally closing the circuit ofsaid air-brake-controlling magnet and being arranged to open saidcircuit only when the current in said excesscurrent magnet exceeds agiven intensity, and a switch actuated by said air-brakecontrollingmagnet, the last mentioned switch having its contacts connected in thecircuit of said excess-current magnet.

21. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brakecontrolling magnetnormally energized by said source, a normally-open-circuitedexcess-current magnet, a switch actuated by said excess-current magnet,said switch controlling the circuit of said air-brake-controllingmagnet, and a switch actuated by said air-brake-controlling magnet forcontrolling the circuit of the excess-current magnet.

22. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brakecontrolling magnetnormally energized by said source, a normally-open-circuitedexcess-current magnet, a switch actuated by said excess-current magnet,said switch normally closing the circuit of said air-brakecontrollingmagnet and being arranged to open said circuit only when the current insaid excess-current magnet exceeds a given intensity, a speed-controlswitch normally closing the circuit of said air-brake-controllingmagnet, a train-carried contact member, and a switch actuated by saidtraincarried contact member and normally closing the circuit of saidair-brake-controlling magnet.

23. A train controlling system comprising in combination a source ofelectrical energy carried by the train, an air-brakecontrolling magnetnormally energized by said source, a normally-open-circuite'dexcess-current magnet, a switch actuated by said excess-current magnet,said switch normally closing the circuit of said air-brake controllingmagnet and being arranged to open said circuit only when the current insaid excess-current magnet exceeds a given intensity, a speed-controlswitch normally closing the circuit of said air-brake-controllingmagnet, a shunt circuit connected around said speed-control switch,means for closing said shunt circuit when the train is stationary or thespeed thereof is less than a predetermined rate, a train-carried contact member and a switch actuated by said train-carried contact memberand normally closing the circuit of said air-brake-controlling magnet.

24. A train controlling system comprising in combination a railroadswitch, means for locking said railroad switch in main-line or switchingposition, a switch locking magnet for actuating said means in onedirection, a

switch-unlocking magnet for actuating said means in the oppositedirection, a traincarried source of electrical energy, and means forclosing the circuit of said source of electrical energy through saidswitchlocking magnet at a point in the block in the rear of that inwhich said railroad switch is located and for closing said circuitthrough said switch-unlocking magnet at a point near said railroadswitch, said means consisting solely of a single train-carried contactmember, a traclceonnected contact member in the block in the rear ofthat in which said railroad switch is located and connected to saidswitclrlocking magnet and a track-connected contact member located at apoint near said railroad switch and connected to said switch-unlockingmagnet.

25. A train controlling system comprising in combination a railroadswitch, means for locking said railroad switch in closed position from apoint in the block in the rear of that in which said railroad switch islocated, and means for unlocking said railroad switch from a point inthe block in which said railroad switch is located, said meanscomprising a train-carried source of electrical energy, atrack-connected contact member in the block in the rear of that in whichsaid railroad switch is located, a track-connected contact member in theblock in which said railroad switch is located, and a train-carriedcontact member arranged to co-operate with both of said track-connectedcontact members.

26. A. train controlling system comprising in combination anelectrically-continuous rail and a sectional rail having a plurality ofsections, each of which is electrically continuous but insulated fromits adjacent sections, and one section divided into two insulatedportions, said portions being insulated from the sections adjacentthereto, a

railroad switch in the block containing the divided sectional rail, saidrailroad switch being located in the advance portion thereof, a shuntcircuit around the proximate ends of said insulated portions, a switchfor opening and closing said shunt circuit, electromagnetic means foractuating said switch, the circuits of said electromagnetic means beingindependent of said shunt circuit, and means comprising a train-carriedsource of electrical energy for energizing said electromagnetic means.

27. A train controlling system comprising in combination anelectrically-continuous rail and a sectional rail having a plurality ofsections, each of which is electrically continuous but insulated fromits adjacent sections, and one section divided into two insulatedportions, said portions being insulated from the sections adjacentthereto,a railroad switch in the block containing the divided sectionalrail, said railroad switch asses being located in the advance portionthereof, a shunt circuit around the proximate ends of said insulatedportions, means for locking said railroad switch in main-line orswitching position, a switch actuated by said means for opening andclosing said shunt circuit, a switch-locking magnet for actuating saidmeans in one direction and a switch-nnlocking magnet tor actuating saidmeans in the opposite direction, the circuits of said switclulockingmagnet and switch-unlocking magnet being independent of said shuntcircuit, and means comprising a train-carried source of electricalenergy for energizing said switch-locking magnet and switch-unlockinmagnet.

28. a train controlling system comprising in combination anelectrically-continuous rail and a sectional rail having a plurality ofsections, each of which is electrically e0ntinuone but insulated fromits adjacent sections, and one section divided into two insulatedportions, said portions being insulated from the sections adjacentthereto, a railroad switch in the block containing the divided sectionalrail, said railroad switch being located in the advance portion thereof,a block resistance electrically connected between the forward end ofsaid advance por tion oi said divided sectional rail and said continuousrail, a track-connected contact member located in the block in the rearof that in which said switch is placed, means connecting saidtrack-connected contact member to the rearward end of the rearwardportion of the divided sectional rail, a shunt circuit around theproximate ends of said insulated portions of said divided sectionalrail, means for locking said railroad switch in main-line or switchingposition, a switch actuated by said means for opening and closing saidshunt circuit, a switch-locking magnet for actuating said means in onedirection and a switch-unlocking magnet for actuating said means in theopposite direction, the circuits of said switch-locking magnet andswitch-unlocking magnet being independent of said shunt circuit and theresistance of each of said magnets being substantially equal to that ofsaid block resistance, a source of electrical energy carried by thetrain, an air-brass-controlling magnet normally energized by saidsource, and a traincarried contact member arranged to connect thecircuit o1 said air-brake controlling magnet in series with saidswitch-locking magnet, said block resistance, and said switch-unlockingmagnet, successively.

29. A train controlling system comprising in combination an electricallycontinuous rail and a sectional rail having a plurality of sections,each of which is electrically continuous but insulated from its adjacentsections, and one section divided into two in sulated portions, saidportions being insu-

